Quantitative study on operation frequency limitation of multi-level high voltage power converter equipped with Si-IEGT and SiC-PiN diode

This paper has quantitatively investigated the operation frequency limitation of high voltage NPC 3-level converter with 4.5 kV Si-IEGT and 5 kV SiC-PiN diode hybrid pair. In order to investigate the limitation, the high speed switching capability of the hybrid pair under a hard drive condition is evaluated, and an exact power loss estimation method is proposed to estimate the power losses of NPC 3-level converter with high voltage bipolar power devices. The possibility of high frequency operation in NPC 3-level converter with the hybrid pair under the hard drive condition is revealed by using the power loss estimation method.